Medium and large scale integrated circuits are commonly formed by the use of groups of photographic plates, often referred to as reticles, which carry photographic images of the different layers of the circuit. Each reticle, which may be five inches square, is typically ten times as large as the integrated circuit to be formed, and a group of perhaps eight reticles may be utilized to define all of the layers of an integrated circuit. The reticles are utilized to make master plates that are used to form the masks utilized in the actual construction of the integrated circuits.
A common technique for producing reticles involves the use of extremely precise mechanisms for moving a reticle holding table in X and Y motions. A computer tape which defines different rectangular areas of the integrated circuit, is utilized to adjust pairs of shutters through which light is directed to fall on the photosensitive reticle. By adjusting the width and length of the rectangular area between shutters, and by adjusting the position of the reticle, a series of many rectangular areas can be formed on the reticle to define the integrated circuit layer. Such equipment is expensive, largely because the reticle must be located with great precision. Also, the circuit must be formed of rectangular areas, which is not always the most efficient form. Although small rectangular areas can be built up to approximate curves, this can greatly increase the time required to form a circuit. The time is considerable, since it may require perhaps one hour to construct each reticle for an integrated circuit of only moderate complexity. An electron beam device with deflection coils has been utilized to record images, but such a particle beam system must be operated in a vacuum, which makes the system costly and cumbersome. A method and apparatus for exposing a reticle, or for any other application in which a precise detailed pattern of light energy was to be applied, which could be constructed at lower cost and operated with ease, would reduce the cost of constructing integrated circuits or any other device utilizing precision patterns.